Characterizing Tris-Ethylenediaminecobalt(III) Iodine in Mixtures of Water and 2-Propanol

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 23 (2018) pp 90-92

Characterizing Tris-Ethylenediaminecobalt(III) Iodide in Mixtures of Water and 2-Propanol

Jaclyn M. Dziewior and James E. House*

Department of Chemistry, Illinois Wesleyan University, Bloomington, IL 61701, jhouse@iwu.edu
Received January 5, 2018. Accepted April 18, 2018.

Published: 12 May 2018

Abstract. An experiment that is frequently carried out in advanced synthesis laboratory courses involves the preparation and characterization of isomers of [Co(en)₃]I₃•H₂O. Two of the usual confirmatory tests for the compound utilize visible range spectroscopy and conductivity, but both techniques are almost always employed with the compound dissolved in water. As an extension of these measurements that are routinely performed, we have investigated the applicability of Beer’s Law and conductivity measurements on solutions of (+)–[Co(en)₃]I₃•H₂O in commercially available mixed solvents containing 50% and 70% of 2-propanol. The results obtained show that although solubility of (+)–[Co(en)₃]I₃•H₂O in these solvents is much lower than it is in water, spectra in the visible range and conductivity measurements in the mixed solvents are useful and informative. Moreover, the results obtained when studying such solutions give insight to the differences in concentration dependence of conductivity of ionic compounds in nonaqueous and mixed solvents.

Key Words: Laboratories and Demonstrations; inorganic chemistry

(*) Corresponding author. (E-mail: jhouse@iwu.edu)

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